Computers and related peripheral equipment, and communication systems, have in the recent past evolved extremely rapidly. These systems require ever increasing data transfer rates to perform the highly complex tasks that is drive the systems, such as digital signal processing, image analysis, and communications. With current demands, optical couplers are used to transfer signals over short and long distances between computers, between two circuit boards in one computer, and even between multiple chips on a single printed circuit board. The use of high speed optical signals in place of electrical interconnections increases the achievable data transfer rate.
In the art today, communication host system like switch or router equipments are usually designed with pluggable interface, for instance, SFP (Small Form-factor Pluggable), XSFP and QSFP are all modules for fiber optic transmission or ordinary signal transmission. All of the modules are of small size or form factor which is important. The smaller the form factor of the module, the less space taken on a printed circuit board to which it couples. A smaller form factor allows a greater number of modules to be coupled onto a printed circuit board to support additional communication channels. Based on industrial standard, cages and sockets on host system are used for accommodating and connecting with standard compliant modules. A connector or module is plugged into the cage and electrical connection established with socket on host. Link between equipments could be setup for communication. Robust and reliable connection is the prerequisite to make the communication system stable. Thus, a latching mechanism is required to keep the connector or module stable within the cage.
As shown in FIG. 1a and FIG. 1b, a conventional pluggable module 100, adapted for engaging with a corresponding cage or module receptacle mounted on a printed circuit board (not shown), generally includes a base 110, a cover 120 and a latching mechanism 130 which has a pair of sliding arms 131 with latching ends 131a and a crosspiece 132 connecting the two sliding arms 131. The base 110 includes two sidewalls 111, each of which has a sliding track 111a formed thereon for receiving the sliding arm 131 of the latching mechanism 130. When pushing or pulling the crosspiece 132, the sliding arms 131 connected to the crosspiece 132 will be actuated to slide along with the tracks 111a and its latching ends 131a will engage with or separate from tabs of the cage (not shown), thereby realizing the latching or releasing for the whole pluggable module 100.
However, the design of above conventional pluggable module results in some drawbacks as follows. Firstly, the two sliding arms of the latching mechanism are required to match with the two tracks of the housing (composed of the base and the cover), thus more complexity process is required for assembly. Secondly, for well latch or de-latch operation, the dimension and tolerance of sliding arms need to meet tight criteria for production and good yield which will increase manufacturing cost. Finally, there is trade-off in sliding arm's thickness design consideration. For rigid concern, sliding arms always need to be thicker, but this will cause the sidewalls of housing to be thick too, finally the PCB area inside the housing will decrease. In the contrast, thinner sliding arms could have wider PCB area, however, quality of parts will be not good for control and tracks on the housing to accommodate sliding arms also not easy to manufacture by simple die-casting process.
Accordingly, it is desired to provide a pluggable module with an improved latching mechanism to overcome the above-mentioned drawbacks.